Ukrainian President Volodymyr Zelensky signed on Tuesday a decree refusing any negotiations with Russian President Vladimir Putin.
The latest move by Kyiv came after the Russian parliament ratified agreements on annexing Ukraine's Donetsk, Kherson, Luhansk and Zaporizhzhia regions.
Last Friday, Putin signed agreements with separatist authorities of the breakaway Ukrainian regions on joining Russia, following referendums held on Sept. 23-27.
The vote comes more than seven months into Russia's war on Ukraine, which began on Feb. 24.
The referendums have been condemned by the international community, with European nations and the US calling them a "sham" and underlining that they would not be recognized.
